Scale Recognition

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There are approximately 64 scales or scale like insects associated with Phragmites worldwide; however, only Chaetococcus phragmitis was reported on Phragmites in North America prior to N. biwakoensis. An additional scale Aclerda holci Teague, has also since been identified on Phragmites in Louisiana. Aclerda holci is native to Louisiana and found on Johnson grass and occasionally sugarcane.

Currently, only A. holci and Nipponaclerda have been found in Phragmites in Louisiana and mature females can be visually distinguished. Both species will often have a mealy wax around the margin of the scale. Adult females of A. holci can be distinguished by their pointed and darkened abdomen from Nipponaclerda which are more uniformly colored with a rounded abdomen.

The native scale does not infest Phragmites in the same numbers as Nipponaclerda, usually only a few individuals per stem, and is currently not believed to be of any concern for the health of the plant. Nipponaclerda are always found with many individuals per stem and infestations can reach over two thousand scales per stem.

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